The invention concerns a plain bearing composite material comprising a supporting layer, optionally a porous carrier layer, in particular made of bronze, and a sliding layer material made of a matrix-forming thermoplastic plastic material and fillers accommodated therein.
Plain bearing composite materials and plain bearings that are produced therefrom and comprise a supporting layer and a plastic sliding layer are well known, in particular in automotive applications. They are used for supporting shafts or shaft journals in cylindrical or bushing-shaped, in particular collar-bushing-shaped bearings. They are also used for spherically designed bearing arrangements. Plain bearing composite materials are typically produced in the form of an endless unit, thereby forming a rollable flat material band. For producing plain bearing elements, blank sections are cut off from an endlessly supplied flat material band of the plain bearing composite material and are then shaped into a bushing or bowl shape. Bushing-shaped plain bearing elements are typically formed having a butt joint which is substantially at least almost completely closed when the plain bearing elements are pressed into a bearing seat.
The fillers accommodated in the thermoplastic matrix of the sliding layer material are tribologically effective substances that have both supporting and wear-reducing properties as well as lubricating properties.
The sliding layer material may be extensively applied to the supporting layer that may be formed, in particular, of steel or aluminium. It could e.g. be laminated, cast or injected. It is, however, also feasible to use a three-dimensionally porous carrier layer that is e.g. porously sintered onto the supporting layer, wherein in this case, the sliding layer material including fillers is impregnated into the open-pored porous carrier layer from the side facing the later sliding partner, thereby improving the retention properties. It thereby typically forms a projection of preferably 50-500 μm past the material of the carrier layer.
It is the underlying purpose of the present invention to further improve a plain bearing composite material of the above-mentioned type with regard to the load-bearing capacity of the sliding layer material.